Astigmatic Vector Analysis of Posterior Corneal Surface - a Comparison Among Healthy, Forme Fruste and Overt Keratoconus Corneas
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Sao Paulo
- Enrollment
- 698
- Locations
- 1
- Primary Endpoint
- Astigmatism corneal vectors (based on keratometric readings at the three millimeter optical zones for both corneal surfaces).
Study Overview
Brief Summary
The main purpose of this study is to determine new diagnostic criteria for an eye disease called keratoconus.
Detailed Description
Eyes of patients who distinctly present signs of keratoconus, for both eyes, at corneal tomography (an exam commonly used in such cases), and those who present such signs in only one eye were compared to eyes of unaffected patients. Several characteristics of anterior and posterior corneal astigmatism (special emphasis was given to the latter) were collectively assessed among all patients by a method referred to as vectorial analysis. Statistical tests were then performed, in an attempt to highlight differences among those three groups of patients and, eventually, define new diagnostic criteria.
Study Design
- Study Type
- Observational
- Observational Model
- Case Control
- Time Perspective
- Retrospective
Eligibility Criteria
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Good-quality Scheimpflug scans (approved by the device in the ''Examination Quality Specification'').
Exclusion Criteria
- •Previous eye surgery or trauma, and any sort of corneal scarring that might interfere with keratometric data acquisition.
Outcomes
Primary Outcomes
Astigmatism corneal vectors (based on keratometric readings at the three millimeter optical zones for both corneal surfaces).
Time Frame: Through study completion, an average of 6 months.
Corneal tomography at an Scheimpflug-based tomographer
Secondary Outcomes
No secondary outcomes reported
Investigators
Giuliano de Oliveira Freitas, MD.
MD
University of Sao Paulo